A series of Alzheimer Disease Study Units (ADSUs) are proposed to carry out clinical trials. Each ADSU will recruit the necessary patients needed to carry out the trial, manage the patients clinically, and maintain appropriate records. The ADSUs will also collect psychometric data to aid in the development of new psychometric instruments. Additionally, each ADSU will be responsible for screening and evaluating data to ensure quality control. Data will then be shipped to the Data Management Core for entry and analysis.